Effect of inorganic ions in heterogeneous photocatalysis of TCE

The influence of 12 ionic compounds (Na2SO4, NaHCO3, Na2HPO3, NaNO3, NaCl, MnCl2, NiCl2, CaCl2, MgCl2, AlCl3, FeCl3, and MgSO4) on performance of a fixed-bed photocatalytic reactor is examined. The fixed-bed photocatalyst was developed at Michigan Technological University and comprises 1% Pt-TiO2 on a silica-based support. The degradation of trichloroethylene (TCE) in Milli-Q water is used to monitor catalyst performance. All compounds are found to inhibit photocatalysis at some or all of the concentrations tested, although only MnCl2 seems to suppress it altogether. Fouling appears to be a least partially reversible. Electron microprobe analysis is employed to investigate how selected fouling agents interact with the catalyst and support.